1 2 /* 3 * IBM ASM Service Processor Device Driver 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 18 * 19 * Copyright (C) IBM Corporation, 2004 20 * 21 * Author: Max Asb�ck <amax@us.ibm.com> 22 * 23 */ 24 25 #include "ibmasm.h" 26 #include "lowlevel.h" 27 28 static void exec_next_command(struct service_processor *sp); 29 30 static atomic_t command_count = ATOMIC_INIT(0); 31 32 struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size) 33 { 34 struct command *cmd; 35 36 if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE) 37 return NULL; 38 39 cmd = kzalloc(sizeof(struct command), GFP_KERNEL); 40 if (cmd == NULL) 41 return NULL; 42 43 44 cmd->buffer = kzalloc(buffer_size, GFP_KERNEL); 45 if (cmd->buffer == NULL) { 46 kfree(cmd); 47 return NULL; 48 } 49 cmd->buffer_size = buffer_size; 50 51 kref_init(&cmd->kref); 52 cmd->lock = &sp->lock; 53 54 cmd->status = IBMASM_CMD_PENDING; 55 init_waitqueue_head(&cmd->wait); 56 INIT_LIST_HEAD(&cmd->queue_node); 57 58 atomic_inc(&command_count); 59 dbg("command count: %d\n", atomic_read(&command_count)); 60 61 return cmd; 62 } 63 64 void ibmasm_free_command(struct kref *kref) 65 { 66 struct command *cmd = to_command(kref); 67 68 list_del(&cmd->queue_node); 69 atomic_dec(&command_count); 70 dbg("command count: %d\n", atomic_read(&command_count)); 71 kfree(cmd->buffer); 72 kfree(cmd); 73 } 74 75 static void enqueue_command(struct service_processor *sp, struct command *cmd) 76 { 77 list_add_tail(&cmd->queue_node, &sp->command_queue); 78 } 79 80 static struct command *dequeue_command(struct service_processor *sp) 81 { 82 struct command *cmd; 83 struct list_head *next; 84 85 if (list_empty(&sp->command_queue)) 86 return NULL; 87 88 next = sp->command_queue.next; 89 list_del_init(next); 90 cmd = list_entry(next, struct command, queue_node); 91 92 return cmd; 93 } 94 95 static inline void do_exec_command(struct service_processor *sp) 96 { 97 char tsbuf[32]; 98 99 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 100 101 if (ibmasm_send_i2o_message(sp)) { 102 sp->current_command->status = IBMASM_CMD_FAILED; 103 wake_up(&sp->current_command->wait); 104 command_put(sp->current_command); 105 exec_next_command(sp); 106 } 107 } 108 109 /** 110 * exec_command 111 * send a command to a service processor 112 * Commands are executed sequentially. One command (sp->current_command) 113 * is sent to the service processor. Once the interrupt handler gets a 114 * message of type command_response, the message is copied into 115 * the current commands buffer, 116 */ 117 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd) 118 { 119 unsigned long flags; 120 char tsbuf[32]; 121 122 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 123 124 spin_lock_irqsave(&sp->lock, flags); 125 126 if (!sp->current_command) { 127 sp->current_command = cmd; 128 command_get(sp->current_command); 129 spin_unlock_irqrestore(&sp->lock, flags); 130 do_exec_command(sp); 131 } else { 132 enqueue_command(sp, cmd); 133 spin_unlock_irqrestore(&sp->lock, flags); 134 } 135 } 136 137 static void exec_next_command(struct service_processor *sp) 138 { 139 unsigned long flags; 140 char tsbuf[32]; 141 142 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 143 144 spin_lock_irqsave(&sp->lock, flags); 145 sp->current_command = dequeue_command(sp); 146 if (sp->current_command) { 147 command_get(sp->current_command); 148 spin_unlock_irqrestore(&sp->lock, flags); 149 do_exec_command(sp); 150 } else { 151 spin_unlock_irqrestore(&sp->lock, flags); 152 } 153 } 154 155 /** 156 * Sleep until a command has failed or a response has been received 157 * and the command status been updated by the interrupt handler. 158 * (see receive_response). 159 */ 160 void ibmasm_wait_for_response(struct command *cmd, int timeout) 161 { 162 wait_event_interruptible_timeout(cmd->wait, 163 cmd->status == IBMASM_CMD_COMPLETE || 164 cmd->status == IBMASM_CMD_FAILED, 165 timeout * HZ); 166 } 167 168 /** 169 * receive_command_response 170 * called by the interrupt handler when a dot command of type command_response 171 * was received. 172 */ 173 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size) 174 { 175 struct command *cmd = sp->current_command; 176 177 if (!sp->current_command) 178 return; 179 180 memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size)); 181 cmd->status = IBMASM_CMD_COMPLETE; 182 wake_up(&sp->current_command->wait); 183 command_put(sp->current_command); 184 exec_next_command(sp); 185 } 186